Posts filed under ‘Infecciones virales’

Strategies used by gay male HIV serodiscordant couples to reduce the risk of HIV transmission from anal intercourse in three countries

Journal of the International AIDS Society March 2019

Introduction

There are few data about the range of strategies used to prevent sexual HIV transmission within gay male serodiscordant couples. We examined HIV prevention strategies used by such couples and compared differences between countries.

Methods

Opposites Attract was a cohort study of male serodiscordant couples in Australia, Brazil and Thailand, from May 2014 (Australia) or May 2016 (Brazil/Thailand) to December 2016. At visits, HIV‐positive partners had viral load (VL) tested; HIV‐negative partners reported sexual behaviour and perceptions of their HIV‐positive partner’s VL results. Within‐couple acts of condomless anal intercourse (CLAI) were categorized by strategy: condom‐protected, biomedically protected (undetectable VL and/or pre‐exposure prophylaxis [PrEP]), or not protected by either (HIV‐negative partners engaging in insertive CLAI, receptive CLAI with withdrawal, or receptive CLAI with ejaculation).

Results

A total of 343 couples were included in this analysis (153 in Australia, 93 in Brazil and 97 in Thailand). Three‐quarters of HIV‐positive partners were consistently virally suppressed (<200 copies/mL) during follow‐up, and HIV‐negative partners had correct perceptions of their partner’s VL result for 76.5% of tests. One‐third of HIV‐negative partners used daily PrEP during follow‐up. Over follow‐up, 73.8% of couples had CLAI. HIV‐negative partners reported 31,532 acts of anal intercourse with their HIV‐positive partner. Of these, 46.7% were protected by condoms, 48.6% by a biomedical strategy and 4.7% of acts were not protected by these strategies. Australian couples had fewer condom‐protected acts and a higher proportion of biomedically protected acts than Brazilian and Thai couples. Of the 1473 CLAI acts where the perceived VL was detectable/unknown and were not protected by PrEP (4.7% of all acts), two‐thirds (n = 983) were when the HIV‐negative partner was insertive (strategic positioning). Of the 490 acts when the HIV‐negative partner was receptive, 261 involved withdrawal and 280 involved ejaculation. Thus, <1% of acts were in the highest risk category of receptive CLAI with ejaculation.

Conclusions

Couples used condoms, PrEP or perceived undetectable VL for prevention in the majority of anal intercourse acts. Only a very small proportion of events were not protected by these strategies. Variation between countries may reflect differences in access to HIV treatment, education, knowledge and attitudes.

FULL TEXT

https://onlinelibrary.wiley.com/doi/10.1002/jia2.25277

PDF

https://onlinelibrary.wiley.com/doi/epdf/10.1002/jia2.25277

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May 14, 2019 at 8:37 am

Risk of HIV transmission through condomless sex in serodifferent gay couples with the HIV-positive partner taking suppressive antiretroviral therapy (PARTNER): final results of a multicentre, prospective, observational study.

LANCET May 2, 2019

Background

The level of evidence for HIV transmission risk through condomless sex in serodifferent gay couples with the HIV-positive partner taking virally suppressive antiretroviral therapy (ART) is limited compared with the evidence available for transmission risk in heterosexual couples. The aim of the second phase of the PARTNER study (PARTNER2) was to provide precise estimates of transmission risk in gay serodifferent partnerships.

Methods

The PARTNER study was a prospective observational study done at 75 sites in 14 European countries. The first phase of the study (PARTNER1; Sept 15, 2010, to May 31, 2014) recruited and followed up both heterosexual and gay serodifferent couples (HIV-positive partner taking suppressive ART) who reported condomless sex, whereas the PARTNER2 extension (to April 30, 2018) recruited and followed up gay couples only. At study visits, data collection included sexual behaviour questionnaires, HIV testing (HIV-negative partner), and HIV-1 viral load testing (HIV-positive partner). If a seroconversion occurred in the HIV-negative partner, anonymised phylogenetic analysis was done to compare HIV-1 pol and env sequences in both partners to identify linked transmissions. Couple-years of follow-up were eligible for inclusion if condomless sex was reported, use of pre-exposure prophylaxis or post-exposure prophylaxis was not reported by the HIV-negative partner, and the HIV-positive partner was virally suppressed (plasma HIV-1 RNA <200 copies per mL) at the most recent visit (within the past year). Incidence rate of HIV transmission was calculated as the number of phylogenetically linked HIV infections that occurred during eligible couple-years of follow-up divided by eligible couple-years of follow-up. Two-sided 95% CIs for the incidence rate of transmission were calculated using exact Poisson methods.

Findings

Between Sept 15, 2010, and July 31, 2017, 972 gay couples were enrolled, of which 782 provided 1593 eligible couple-years of follow-up with a median follow-up of 2·0 years (IQR 1·1–3·5). At baseline, median age for HIV-positive partners was 40 years (IQR 33–46) and couples reported condomless sex for a median of 1·0 years (IQR 0·4–2·9). During eligible couple-years of follow-up, couples reported condomless anal sex a total of 76 088 times. 288 (37%) of 777 HIV-negative men reported condomless sex with other partners. 15 new HIV infections occurred during eligible couple-years of follow-up, but none were phylogenetically linked within-couple transmissions, resulting in an HIV transmission rate of zero (upper 95% CI 0·23 per 100 couple-years of follow-up).

Interpretation

Our results provide a similar level of evidence on viral suppression and HIV transmission risk for gay men to that previously generated for heterosexual couples and suggest that the risk of HIV transmission in gay couples through condomless sex when HIV viral load is suppressed is effectively zero. Our findings support the message of the U=U (undetectable equals untransmittable) campaign, and the benefits of early testing and treatment for HIV.

Funding

National Institute for Health Research.

FULL TEXT

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(19)30418-0/fulltext

May 6, 2019 at 7:16 am

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza.

Clinical Infectious Diseases March 5, 2019 V.68 N.6 P.e1-e47.   

Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza.

Uyeki TM1, Bernstein HH2, Bradley JS3,4, Englund JA5, File TM6, Fry AM1, Gravenstein S7, Hayden FG8, Harper SA9, Hirshon JM10, Ison MG11, Johnston BL12, Knight SL13, McGeer A14, Riley LE15, Wolfe CR16, Alexander PE17,18, Pavia AT19.

Abstract

These clinical practice guidelines are an update of the guidelines published by the Infectious Diseases Society of America (IDSA) in 2009, prior to the 2009 H1N1 influenza pandemic. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. It is intended for use by primary care clinicians, obstetricians, emergency medicine providers, hospitalists, laboratorians, and infectious disease specialists, as well as other clinicians managing patients with suspected or laboratory-confirmed influenza. The guidelines consider the care of children and adults, including special populations such as pregnant and postpartum women and immunocompromised patients.

Published by Oxford University Press for the Infectious Diseases Society of America 2018.

FULL TEXT

https://academic.oup.com/cid/article/68/6/e1/5251935

PDF (CLIC en PDF)

May 1, 2019 at 6:23 pm

Measles in 2019 — Going Backward

N Engl J of Medic April 18, 2019

C.I. Paules, H.D. Marston, and A.S. Fauci

In 2000, the United States achieved a historic public health goal: the elimination of measles, defined by the absence of sustained transmission of the virus for more than 12 months. This achievement resulted from a concerted effort by health care practitioners and families alike, working to protect the population through widespread immunization…..

FULL TEXT

https://www.nejm.org/doi/full/10.1056/NEJMp1905099?query=TOC

PDF

https://www.nejm.org/doi/pdf/10.1056/NEJMp1905099?articleTools

 

April 21, 2019 at 11:39 am

Cost-effectiveness analysis of quadrivalent seasonal influenza vaccines in England.

BMC Med. September 8, 2017 V.15 N.1 P.166.

Thorrington D1, van Leeuwen E2,3, Ramsay M4, Pebody R2, Baguelin M2,5.

Author information

1 Respiratory Diseases Department, Public Health England, 61 Colindale Avenue, London, NW9 5EQ, UK. dominic.thorrington@phe.gov.uk

2 Respiratory Diseases Department, Public Health England, 61 Colindale Avenue, London, NW9 5EQ, UK.

3 Imperial College Faculty of Medicine, London, SW7 2AZ, UK.

4 Immunisation, Hepatitis & Blood Safety Department, Public Health England, 61 Colindale Avenue, London, NW9 5EQ, UK.

5 Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.

Abstract

BACKGROUND:

As part of the national seasonal influenza vaccination programme in England and Wales, children receive a quadrivalent vaccine offering protection against two influenza A strains and two influenza B strains. Healthy children receive a quadrivalent live attenuated influenza vaccine (QLAIV), whilst children with contraindications receive the quadrivalent inactivated influenza vaccine (QIIV). Individuals aged younger than 65 years in the clinical risk populations and elderly individuals aged 65+ years receive either a trivalent inactivated influenza vaccine (TIIV) offering protection from two A strains and one B strain or the QIIV at the choice of their general practitioner. The cost-effectiveness of quadrivalent vaccine programmes is an open question. The original analysis that supported the paediatric programme only considered a trivalent live attenuated vaccine (LAIV). The cost-effectiveness of the QIIV to other patients has not been established. We sought to estimate the cost-effectiveness of these programmes, establishing a maximum incremental total cost per dose of quadrivalent vaccines over trivalent vaccines.

METHODS:

We used the same mathematical model as the analysis that recommended the introduction of the paediatric influenza vaccination programme. The incremental cost of the quadrivalent vaccine is the additional cost over that of the existing trivalent vaccine currently in use.

RESULTS:

Introducing quadrivalent vaccines can be cost-effective for all targeted groups. However, the cost-effectiveness of the programme is dependent on the choice of target cohort and the cost of the vaccines: the paediatric programme is cost-effective with an increased cost of £6.36 per dose, though an extension to clinical risk individuals younger than 65 years old and further to all elderly individuals means the maximum incremental cost is £1.84 and £0.20 per dose respectively.

CONCLUSIONS:

Quadrivalent influenza vaccines will bring substantial health benefits, as they are cost-effective in particular target groups.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5590113/pdf/12916_2017_Article_932.pdf

April 13, 2019 at 12:58 pm

A review of the value of quadrivalent influenza vaccines and their potential contribution to influenza control.

Hum Vaccin Immunother. July 3, 2017 V.13 N.7 P.1640-1652.

Ray R1, Dos Santos G2, Buck PO3, Claeys C1, Matias G1, Innis BL3, Bekkat-Berkani R1.

Author information

1 a GSK , Wavre , Belgium.

2 b Business & Decision Life Sciences , Brussels , Belgium (on behalf of GSK).

3 c GSK , Philadelphia , PA , USA.

Abstract

The contribution of influenza B to the seasonal influenza burden varies from year-to-year. Although 2 antigenically distinct influenza B virus lineages have co-circulated since 2001, trivalent influenza vaccines (TIVs) contain antigens from only one influenza B virus. B-mismatch or co-circulation of both B lineages results in increased morbidity and mortality attributable to the B lineage absent from the vaccine. Quadrivalent vaccines (QIVs) contain both influenza B lineages. We reviewed currently licensed QIVs and their value by focusing on the preventable disease burden. Modeling studies support that QIVs are expected to prevent more influenza cases, hospitalisations and deaths than TIVs, although estimates of the case numbers prevented vary according to local specificities. The value of QIVs is demonstrated by their capacity to broaden the immune response and reduce the likelihood of a B-mismatched season. Some health authorities have preferentially recommended QIVs over TIVs in their influenza prevention programmes.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5512791/pdf/khvi-13-07-1313375.pdf

 

April 13, 2019 at 12:57 pm

Safety and Immunogenicity of MF59-Adjuvanted Cell Culture-Derived A/H5N1 Subunit Influenza Virus Vaccine: Dose-Finding Clinical Trials in Adults and the Elderly.

 Open Forum Infect Dis. March 1, 2019 V.6 N.4 

Frey SE1, Shakib S2, Chanthavanich P3, Richmond P4, Smith T5, Tantawichien T6, Kittel C7, Jaehnig P7, Mojares Z8, Verma B9, Kanesa-Thasan N9, Hohenboken M10.

Author information

1 School of Medicine, Saint Louis University, St. Louis, Missouri.

2 CMAX Clinical Research Pty Ltd., Adelaide, SA, Australia.

3 Department of Tropical Pediatrics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.

4 Division of Paediatrics, School of Medicine, University of Western Australia, and Vaccine Trials Group, Telethon Kids Institute, Subiaco, WA, Australia.

5 Mercy Health Research, St. Louis, Missouri.

6 Department of Medicine, Faculty of Medicine, Chulalongkorn University and Queen Saovabha Memorial Institute, Bangkok, Thailand.

7 GlaxoSmithKline Vaccines GmbH, Marburg, Germany.

8 GlaxoSmithKline Pte Ltd., Singapore, Singapore.

9 GlaxoSmithKline Vaccines LLC, Rockville, Maryland.

10 Seqirus Inc., Cambridge, Massachusetts.

Abstract

BACKGROUND:

A/H5N1 influenza viruses have high pandemic potential; consequently, vaccines need to be produced rapidly. MF59® adjuvant reduces the antigen required per dose, allowing for dose sparing and more rapid vaccine availability.

METHODS:

Two multicenter, phase II trials were conducted to evaluate the safety and immunogenicity of an MF59-adjuvanted, cell culture-derived, A/H5N1 vaccine (aH5N1c) among 979 adult (18-64 years old) and 1393 elderly (≥65 years old) subjects. Participants were equally randomized to receive 2 full-dose (7.5 μg of hemagglutinin antigen per dose) or 2 half-dose aH5N1c vaccinations 3 weeks apart. Outcomes were based on Center for Biologics Evaluation Research and Review (CBER) and Committee for Medicinal Products for Human Use (CHMP) licensure criteria (titers ≥1:40 and seroconversions on day 43). Solicited reactions and adverse events were assessed (www.clinicaltrials.gov: NCT01776541 and NCT01766921).

RESULTS:

CBER and CHMP criteria were met by both age groups. CBER criteria for hemagglutination titers were met for the full-dose formulation. Solicited reaction frequencies tended to be higher in the full-dose group and were of mild to moderate intensity. No vaccine-related serious adverse events occurred.

CONCLUSIONS:

In adult and elderly participants, the full-dose aH5N1c vaccine formulation was well tolerated and met US and European licensure criteria for pandemic vaccines.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6446137/pdf/ofz107.pdf

April 13, 2019 at 12:56 pm

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